Switch structure



Oct. 14, 1952 R. F. LESTER 2,614,194

SWITCH STRUCTURE Filed Feb. 7, 1950 IN VEN TOR. /{YZWZZ Patented Oct. 14, 1952 SWITCH STRUCTURE Itay F. Lester, Syracuse, N. Y., assignor to Crousey Hinds Company, Syracuse, N. Y., a corporation of New York Application February 7, 1950, Serial No. 142,732

4 Claims. (Ci. ZOO- 159) This invention relates to electric switches and more particularly to switches of the type wherein the contacts are moved into and out of engagement by push button operation. Such switches are used extensively in industrial applications, the switch proper being mounted in an enclosed housing with an actuating member operable externally of the housing to effect axial movement of the stem of the switch.

When the stem of the switch has been moved axially a suliicient distance to eiect engagement of the contacts of the switch, further movement of the stem would injure the mechanism of the switch. To avoid over actuation of the movable members of the switch, it has been the practice to embody mechanism in the housing between the stem of the switch and the operating manual to permit over-travel of the manual or push button without exerting any undue pressure on the movable mechanism of the switch after the contacts have been closed. These over-run mechanisms add to the size of the structure of the switch unit and materially increase the cost thereof.

In certain applications, switches of the type referred to embody an exceedingly compact structure in order that the switch proper may be mounted in a small housing and, in such instances, it is exceedingly diicult, if not impossible, to include any additional over-run mechanism.

This invention has as an object a switch of the type referred to embodying a structure within the switch proper which functions to permit overtravel of the stem member of the switch without any injurous effect on the contact mechanism, thus alleviating the necessity of any over-run mechanism between the switch and the operating manual.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is a vertical sectional view of a switch embodying my invention, the section being taken diametrically on a line corresponding to line l-l, Figure 2.

Figure 2 is a transverse sectional View taken on line 2 2, Figure l.

Figure 3 is a view, similar to Figure 2, taken on line 3-3, Figure 1.

Figure 4 is a vertical sectional view taken on line 4 4, Figure 3.

The switch consists of a body member lll formed 2 of insulating material. As disclosed in the drawings, the body I is of cylindrical formation-'and is mounted in a cylindrical body I-l l by being threaded therein, as disclosed in Figures l and k4, the body l0 forming a closure for the open end of the housing ll, and the opposite end of'the housing is formed witha cylindrical boss l 2.1 The housing Il may be mounted in a panel i3 vby positioning the boss l2 in van aperture in the panel and threading a locknut i4 on the boss engaging the front side of the panel. v

The body Ill is formed with a recess and with diametrically opposedprojections l5 arranged in the recess and extending upwardly from the bottom wall thereof and terminating short of thfe upper end of the body. The body is also formed with a bore Il located centrallyin the bottom wall of the recess. A pair of arcuate shaped contacts I 3 are iixedly mounted'on the bottom wall of the recess between the projections .'j. Each oi' the contacts l 8,L is flxedly secured to a metallic insert i9 moulded in the bodyand provided at its lowerex'p'osed end with a binding screw 2B. A pair o1" xed contacts 2l vare'mounted onthe upper ends of the projections. [6." The contacts 2i are vsecured' to the upper end of metallic inserts 22 moulded in the bodyl and being provided at their lower exposed ends with binding screws 23. The contacts v2l are also arcuate shaped and are 4secured to the inserts 22 by screws 2d.

'The pairs of contacts It, 2l are engaged by contacts 25 carried on radially extendingportions 26 of a `bridge member 2l. The radially extending portions 26 of the bridge member are positioned` between the projectionsV I6 of the body. The bridge member 2lk is slidably mounted upon a stem 30 mounted in the body for axial movement, to move thecontacts 25 carried bythe bridge member alternatively into engagement with the contacts IS, 2l. The contacts i8, 2l are arranged in vertical registration and the contacts 25 carried by the bridge member are movable axially in registration with the xed contacts and so maintained inasmuch as the-projectionsll prevent rotation of the bridge member 21 about the axis of the stem 3l). Y. e n v The stem 30 is provided with a;l stop-to `limit axial movement of the bridgemember onthe stem in a direction towardlthe bottom-contacts I8. Inthe arrangementshown, thestem is formed with a lower enlarged portion 3| slidably mounted in the bore il and which forms a shoulder stop against which the bridge plate 21 is positioned. The enlarged portion 3l is formed with an axial recess in which is arranged a compression spring 33 acting between the stem and the bottom of the bore I 'I and which functions to yieldingly urge the stem upwardly and the contacts into engagement with the upperI contacts 2|.

The upper. portion of the stem is encircled by a sieeve.35 slidably mounted on the stem and recessed at its upper end to accommodate a compression spring 36 encircling the stem 30 and act-Y ing against the head of a screw 31 threaded into the upper end of the stem.

With this arrangement, they bridge plate. 21 is yieldingly urged against the stopy shoulder formed by the enlargement 3 I.

The stem 30 and sleeve 35 are formed of. dielectric material, such as liber. ItWill be apparent that upon downward axial movement of the stem 30, the bridge plate 2'I is moved downwardly, moving thev contacts 25 intoengagement with. theA lower contacts I8. Upon continued downward movement of the stem30, the bridge member 2'I and theA sleeve-35 slide axially upon the stexnagainst the actionof the compression spring. 36,'. thusV permittingl over-running of the stem.

The stem 30 may. be extended outwardly throughl the housing, but preferably axial movement of the stem is eifected by an actuating member 40 arranged in coaxial relation with the stem and being slidably mounted in a bushing- 4I threaded into the hub portion I2 of the housing. The structural arrangement described prevents damage to the bridge plate 21 in the event the actuating member 40 and stem 30 are moved inwardly after the contacts 25 have engazed the contacts I8;

It. will be apparent that the structure for mounting the bridge plate on the stem is not only economical to.. manufacture but is confined within. the switch proper and does'not require anyadditional spacel within the housing in which the switch is mounted;

WhatI claim is:

1. A switch comprising a body' formed with a recess', a pair of iixed contacts mounted in spaced'. relation at the bottom of said recess, a second pair of fixed` contacts mounted in said recess and' arranged above said first pair of contacts', aI stem slidably mounted in the body for axial movement in said recess and being formed with a stop, a bridging contact slidably mounterlon` said stem, spring means yieldingly urging said steinl to move said bridging contact into engagement with said second pair of xed conr ltacts, a sleeve encircling said stem and having sliding engagement with said stem and the wall portions of said recess, spring means cooperable withl said stem and'sleeve to yieldingly urge said sleeve againstsaid bridging contact andthe latter against said stop, and an actuating member operable to effect axial movement of said stem toward said first pair of contacts.

2. A switch comprising a body formed with a recess, aI pair of contacts xedly mounted at the bottom of'said recess, a second pair of contacts ilxedly mounted in said recess and being spaced axially thereof in relation to said rst contacts, a stern slidably mounted in the body for axial movement in said recess and being formed with a stop, a bridging contact mounted on the stem 0 Number against said stop and being movable axially on the stem away from said stop, said movable contact having portions slidably engaging the wall of said recess and being cooperable to restrain said movable contact against rotation, a spring cooperable with said stem to yieldingly maintain said bridging contact against said. second xed contacts,y ay sleeve encircling the stem, spring means cooperable with said stem and sleeve to yieldingly urge said bridging contact against said stop, and an actuating member operable to effect axial movement of the stem toward said rstxed contacts.

3. Aswitchcomprising a body formed with a recess, arpairv of contacts mounted in the recess andbeing spaced apart axially thereof, a stem slidably mounted in the body for axial movement in said recess, a movable contact carried by the stem and being movable upon reciprocation of said stem alternately into engagement with said xed contacts, said stem being provided with a stop and a sleeve having sliding engagementl with said stem and theside' wall portions of said recess, said movable contact being mounted on the stem intermediate said stop and sleeve, spring means cooperable with the stem and sleeve to yieldingly maintainA said movable contact against said stop, an actuating member operable to effect axial movement of said stem in one direction, and spring means operable to effect axial movement of said stem in the opposite direction.

4. A switch comprising a body formed with a recess, a pair of lower contacts xedly mounted in proximity to the bottom wall of said recess, a pair of upper contacts xedly mounted in said recess above said lower contacts, a central' bore formed in the bottom wall of said recess, a stem having an enlarged end portion slidably mounted in said bore, a bridging'contact slidably mounted on the stem and being formed' with projections slidably engaging withy the side wall portions of the recess, a sleeve slidably mounted on said: stem and having sliding contact with the side wall portions of the recess, springmeans cooperable with said, stern and sleeve to yieldingl'yy urge said sleeve against said contact and the latter against the enlarged end portionof the stem, a second spring-v positioned in said bore and` yieldingly urging said stem upwardly and maintaining said bridging contact in engagement with said upper contacts, and actuating means operable to effect downward movement of the stem to move said bridging contact into engagement with said lower xedcontacts.

RAY'F.' LESTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITEDv STATES.. PATENTS Name Date. Sawyer Feb.v 20, 1877 Kintzing June 9, 1942 Von Mehren Dec. 1, 1942 Ballon Feb. 27,195.1

FOREIGN PATENTS Country Date Germany Mar. 25, 1926 Number 

